Field of the Disclosure
The following is directed to abrasive articles including abrasive particulate materials, and particularly, abrasive particulate materials having particular compositions and shapes.
Description of the Related Art
High performance abrasive materials and components have long been used in various industrial-machining applications, including lapping/grinding, in which bulk material removal is executed, to fine polishing, in which fine micron and submicron surface irregularities are addressed. Typical materials that undergo such machining operations include various ceramics, glasses, glass-ceramics, metals and metal alloys. Abrasives may take on any one of various forms, such as free abrasives, which can include abrasive particulate material in a slurry. Alternatively, such abrasive particulate material may be incorporated into various matrix structures to form a fixed abrasive, such as a coated abrasive or a bonded abrasive. Coated abrasives are generally categorized as abrasive components having an underlying substrate, on which abrasive grits or grains are adhered thereto through a series of make coats and size coats. Bonded abrasives typically do not have an underlying substrate and are formed of an integral structure of abrasive grits that are bonded together via a matrix bonding material.
Particular portions of the industry are most interested in aluminous materials, typically alpha-alumina material for use in abrasive applications. Alpha alumina may be formed through conversion of an aluminous precursor, typically at a temperature on the order of 1000° C. to 1200° C. See, for example, Harato et al. (U.S. Pat. No. 5,302,368) and Kaisaki et al. (U.S. Pat. No. 6,194,317). Abrasive compounds containing primarily alpha alumina are useful in polishing metal surfaces at high material removal rates. Alpha alumina is the hardest phase of polycrystalline alumina and provides a desirably high material removal rate, however its use is limited to certain applications due to poor selectivity and tendencies to produce undesirable surface defects such as scratches and orange peel.
The industry continues to demand improved abrasive particulate materials that can be incorporated into various fixed abrasive articles.